"So glad you found some information but I'm distressed to realize that you have never searched the Names Index database on the California Genealogical Society website. If you had you would have already known about the IOOF records for Dora and Frederick. We have records for the four surnames you mentioned. We need to get you up here to Oakland for a day of digging!"
I don't recall visiting the CGSL website before, so I took the opportunity to do that and see what records they have indexed for the surnames McKnew, Schaffner, Paul, Whittle and Seaver. Here is the Name Search and Order page on the CGSL site:
I entered the surname "Whittle" in the search field and clicked on "Search." The results for Whittle came back as:
Hey, lookee there - a Joseph Whittle died in 1871, age 46. That is, I think, my wife's second great-grandfather, born in England, migrated to the Bay Area from Australia around 1850. The list above provides a source as "Early Death" and requests a fee of $10 to look up and provide the record. The CGSL Lookup Order Form permits the user to request lookups found in the Name Index or in the Library References.
I wondered if the specific Joseph Whittle entry might be in the death records listed on the San Francisco Genealogy website, so I checked there. On the Vitals Records Index page is a link for San Francisco Pre-1905 Deaths, shown below:
I clicked on the Pre-1905 Deaths database link, and then selected the 6 Jun 1871 to 11 September 1871 link, saw (after using the Edit > Find for "Whittle"):
Death Date = 2 Sep 1871
I checked several more databases for Joseph Whittle, and found an entry in the 1867 Great Register of San Francsico that said:
Name = Whittle, Joseph
Okay, all of that matches pretty well with what I've found in the San Francisco City Directories on Footnote.com. Now that I had a death date, I went searching for a death notice or obituary in the San Francisco Chronicle on http://www.footnote.com/. Using the search engine on Footnote.com for [Whittle] and [Joseph Whittle] did not find any matches, even in the early September issues. Oh well!
After these searches, I did a search on Google using the search string ["whittle joseph" "san francisco"] and found both of the records above, plus some message board posts about Joseph Whittle (which I had seen before).
Now the problem with the Whittle line is "what became of Joseph's wife, Rachel (Moore) Whittle." She doesn't show up in any searches on the CGSL site or the San Francisco Genealogy site.
My conclusion here is that at least some of the items that show up in the CGSL Names Index search can be found in other resources, especially on the San Francisco Genealogy website.
I really appreciate the CGSL Names Search capability and the San Francisco Genealogy website. What an excellent service to distant genealogy researchers. If researchers want data lookups from these databases, they can obtain them for a nominal fee.
Thank you, Kathryn, for the very helpful comment and to CGSL for the website.